Known for both its narrative style and scientific rigor, Principles of Behavior is the premier introduction to behavior analysis. Through an exploration of experimental, applied, and theoretical concepts, the authors summarize the key conversations in the field. They bring the content to life using humorous and engaging language and show students how the principles of behavior relate to their everyday lives. The text’s tried-and-true pedagogy make the content as clear as possible without oversimplifying the concepts. Each chapter includes study objectives, key terms, and review questions that encourage students to check their understanding before moving on, and incorporated throughout the text are real-world examples and case studies to illustrate key concepts and principles. This edition features some significant organizational changes: the respondent conditioning chapter is now Chapter 1, a general introduction to operant conditioning is now covered in Chapters 2 and 3, and the introduction to research methods is now covered in Chapter 4. These changes were made to help instructors prepare students for starting a research project at the beginning of the course. Two new chapters include Chapter 5 on the philosophy supporting behavior analysis, and Chapter 24 on verbal behavior that introduces B.F. Skinner’s approach and terminology. This edition also features a new full-color design and over 400 color figures, tables, and graphs. Principles of Behavior is an essential resource for both introductory and intermediate courses in behavior analysis. It is carefully tailored to the length of a standard academic semester and how behavior analysis courses are taught, with each section corresponding to a week’s worth of coursework. The text can also function as the first step in a student’s journey into becoming a professional behavior analyst at the BA, MA, or PhD/EdD level. Each chapter of the text is integrated with the Behavior Analyst Certification Board (BACB) task list, serving as an excellent primer to many of the BACB tasks.